﻿/*******************************************************************************************
 * Copyright (c) 2009 Alex Robson, Rob Simmons, Craig Israel, and Rachel Twyford
 *
 * Use of this software in any form requires that you have both 
 * read and agreed to the following terms:
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions: 
 *
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, 
 * this list of conditions and the following disclaimer in the 
 * documentation and/or other materials provided with the distribution.
 * Neither the name of Nvigorate nor the names of its contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL ANY CONTRIBUTOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ****************************************************************************************/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using Nvigorate.Xml;

namespace Nvigorate.Data.Query
{
    [Serializable]
    public class Function : QueryObject<Function>
    {
        protected List<IQueryObject> _parameters = new List<IQueryObject>();

        public List<IQueryObject> ParameterList
        {
            get { return _parameters; }
            set { _parameters = value; }
        }

        public Function Parameters(params IQueryObject[] parameters)
        {
            _parameters.AddRange(parameters);
            return this;
        }

        #region Overrides of QueryComponent

        public override XElement GetXElementRepresentation()
        {
            return new XElement("function",
                    new XAttribute("name", _name),
                    new XAttribute("alias", _alias),
                    new XAttribute("owner", _owner),
                    new XElement("parameters", _parameters.Select(p => p.GetXElementRepresentation()))
                );
        }

        public override object ParseXElement(XElement element)
        {
            _name = element.GetAttributeValue("name") ?? "";
            _alias = element.GetAttributeValue("alias") ?? "";
            _owner = element.GetAttributeValue("owner") ?? "";

            var parameters = element.Element("parameters");

            if(parameters != null)
                _parameters
                    .AddRange(parameters.Descendants()
                    .Select(p => QueryDeserializer.DeserializeAmbiguousChild<IQueryObject>(p)));

            return this;
        }

        #endregion

        public static Function UDF(string functionName)
        {
            return new Function(functionName);
        }

        public static Function NewId()
        {
            return new Function("NEWID");
        }

        public static Function GetDate()
        {
            return new Function("GETDATE");
        }

        public static Function LeftTrim()
        {
            return new Function("LTRIM");
        }

        public static Function RightTrim()
        {
            return new Function("RTRIM");
        }

        public static Function SubString()
        {
            return new Function("SUBSTRING");
        }

        public static Function Left()
        {
            return new Function("LEFT");
        }

        public static Function Right()
        {
            return new Function("RIGHT");
        }

        public static Function Min(IQueryObject argument)
        {
            return new Function("MIN").Parameters(argument);
        }

        public static Function Max(IQueryObject argument)
        {
            return new Function("MAX").Parameters(argument);
        }

        public Function()
        {
            
        }

        internal Function(string functionName)
        {
            _name = functionName;
        }
    }
}
